©BRIGHTSTARS 2025 ALL RIGHTS RESERVED 9:46 AM A+
Molecular Cell Biology - Final Exam Study
Guide 100% Verified.
Gamma-Turc - Answer✔This protein complex is recruited to microtubule organizing centers in
order to promote nucleation of microtubules, and to act as a minus end cap which prevents
microtubule disassembly after GTP hydrolysis.
Myosin - Answer✔This plus-end directed microfilament motor protein promotes vesicle
movement and cell contraction.
Kinesin - Answer✔This plus-end directed microtubule motor protein helps to promote
movement and positioning of cytoplasmic organelles and vesicles.
Microtubule - Answer✔This polarized filament network forms dynamic, but rigid, structures
that are primarily used for transport and positioning of cytoplasmic organelles and vesicles.
Microfilament - Answer✔This polarized filament network forms a diverse range of filament
structures that can promote cell migration, contraction, adhesion and cellular structure.
Alpha-actinin - Answer✔This protein promotes formation of parallel microfilament arrays found
in contractive fibers of muscle cells as well as migrating cells.
Tropomodulin - Answer✔This minus end capping protein prevents growth/shrinkage of actin
filaments in contractive fibers of muscle cells and migrating cells:
1
, ©BRIGHTSTARS 2025 ALL RIGHTS RESERVED 9:46 AM A+
G-protein coupled receptor - Answer✔Binding of a ligand to these membrane proteins activates
their GEF activity so that the Galpha subunit of trimeric G-proteins they associate with become
activated.
Adenylate Cyclase - Answer✔This protein functions both to generate cAMP and as a GAP to
activate GTPase activity of a bound Galpha protein.
Protein Kinase A (PKA) or cAMP dependent protein kinase - Answer✔Activation of this protein
by association with a 2nd messenger, such as cAMP, results in phosphorylation of substrates
that alter function of cytosolic proteins to quickly change cell behavior as well as nuclear
proteins to have long-term effects on cell behavior.
Cyclin A/B - Answer✔This protein positively regulates CDK1 so it become active and promotes
entry into M-phase.
Cdc20 - Answer✔This protein allows progression from metaphase to anaphase by allowing the
E3 ligase, APC, to associate with securin and target it for poly-ubiquitination.
Cdh1 - Answer✔This protein promotes progression through anaphase by allowing the E3 ligase,
APC, to associate with cyclins A&B so that CDK1 can no longer phosphorylate targets that
promote chromatin condensation and nuclear envelope breakdown.
Caspase - Answer✔This is a protease that mediates apoptosis by degrading both nuclear and
cytosolic targets.
G0-phase - Answer✔This term refers to a stage in the cell cycle where the cell is quiescent, or
not actively undergoing steps to divide.
Apoptosome - Answer✔This term refers to the large protein structure that activates pro-
caspases and forms when cytochrome c is released from the mitochondrial inner membrane of
mammalian cells.
2
Molecular Cell Biology - Final Exam Study
Guide 100% Verified.
Gamma-Turc - Answer✔This protein complex is recruited to microtubule organizing centers in
order to promote nucleation of microtubules, and to act as a minus end cap which prevents
microtubule disassembly after GTP hydrolysis.
Myosin - Answer✔This plus-end directed microfilament motor protein promotes vesicle
movement and cell contraction.
Kinesin - Answer✔This plus-end directed microtubule motor protein helps to promote
movement and positioning of cytoplasmic organelles and vesicles.
Microtubule - Answer✔This polarized filament network forms dynamic, but rigid, structures
that are primarily used for transport and positioning of cytoplasmic organelles and vesicles.
Microfilament - Answer✔This polarized filament network forms a diverse range of filament
structures that can promote cell migration, contraction, adhesion and cellular structure.
Alpha-actinin - Answer✔This protein promotes formation of parallel microfilament arrays found
in contractive fibers of muscle cells as well as migrating cells.
Tropomodulin - Answer✔This minus end capping protein prevents growth/shrinkage of actin
filaments in contractive fibers of muscle cells and migrating cells:
1
, ©BRIGHTSTARS 2025 ALL RIGHTS RESERVED 9:46 AM A+
G-protein coupled receptor - Answer✔Binding of a ligand to these membrane proteins activates
their GEF activity so that the Galpha subunit of trimeric G-proteins they associate with become
activated.
Adenylate Cyclase - Answer✔This protein functions both to generate cAMP and as a GAP to
activate GTPase activity of a bound Galpha protein.
Protein Kinase A (PKA) or cAMP dependent protein kinase - Answer✔Activation of this protein
by association with a 2nd messenger, such as cAMP, results in phosphorylation of substrates
that alter function of cytosolic proteins to quickly change cell behavior as well as nuclear
proteins to have long-term effects on cell behavior.
Cyclin A/B - Answer✔This protein positively regulates CDK1 so it become active and promotes
entry into M-phase.
Cdc20 - Answer✔This protein allows progression from metaphase to anaphase by allowing the
E3 ligase, APC, to associate with securin and target it for poly-ubiquitination.
Cdh1 - Answer✔This protein promotes progression through anaphase by allowing the E3 ligase,
APC, to associate with cyclins A&B so that CDK1 can no longer phosphorylate targets that
promote chromatin condensation and nuclear envelope breakdown.
Caspase - Answer✔This is a protease that mediates apoptosis by degrading both nuclear and
cytosolic targets.
G0-phase - Answer✔This term refers to a stage in the cell cycle where the cell is quiescent, or
not actively undergoing steps to divide.
Apoptosome - Answer✔This term refers to the large protein structure that activates pro-
caspases and forms when cytochrome c is released from the mitochondrial inner membrane of
mammalian cells.
2
